1. Field
Embodiments of the present invention relate to integrated circuit devices and, in particular, to phase-locked loops.
2. Discussion of Related Art
Integrated circuits, such as communication chips, microprocessors, micro-controllers, and/or other devices, often operate at relatively high frequency. The frequency may be in the gigahertz (GHz) range, and future generations of devices may operate even faster.
The devices' operation may be stabilized by a clock source. The clock source may have a phase-locked loop. A phase-locked loop is a circuit or device that compares the phase of two signals, such as for example, a reference signal and a voltage-controlled signal. A phase difference between the two signals produces an error voltage that locks the frequency of the voltage-controlled signal to that of the reference signal. Traditional phase-locked loops have limitations, however.